A group of anglers with a haul of snapper 45 times over the daily limit will face prosecution - and their boat has been seized by Ministry for Primary Industries.

The group of five were caught by MPI Fishery Offices with 348 fish - 317 of which were snapper, weighing in at 200kg.

They were stopped by officers doing boat inspections at the Half Moon Bay boat ramp in East Auckland.

The daily limit for catching snapper on the east coast of Auckland in the Hauraki Gulf is seven per person with a minimum size of 30cm.

Andre Espinoza, MPI's West North Island regional manager fish compliance, said 95 of the snapper the group had caught were undersized.

"When people take this obviously illegal haul of fish - along with many of them being undersize – they threaten the sustainability of the fishery," said Espinoza.

"The rules are there for a reason and when we find evidence of deliberate rule-breaking, you can be assured we will take action."

He said MPI encourages all recreational fishers to know the fishing rules for their area and advised that the best way to do this was to download the NZ Fishing Rules app.

"We work hard to protect fishing resources so that current and future generations can enjoy catching a feed of kaimoana," said Espinoza.